[Zodb-checkins] SVN: ZODB/branches/shane-poll-invalidations/src/ZODB/ Added the invalidation polling patch that RelStorage depends on.
Shane Hathaway
shane at hathawaymix.org
Fri Dec 12 16:13:38 EST 2008
Log message for revision 94005:
Added the invalidation polling patch that RelStorage depends on.
Included a new interface (IStoragePollable), a variant of MappingStorage
that depends on polling, and a fairly thorough test.
Changed:
U ZODB/branches/shane-poll-invalidations/src/ZODB/Connection.py
U ZODB/branches/shane-poll-invalidations/src/ZODB/DB.py
U ZODB/branches/shane-poll-invalidations/src/ZODB/MappingStorage.py
A ZODB/branches/shane-poll-invalidations/src/ZODB/PollableMappingStorage.py
U ZODB/branches/shane-poll-invalidations/src/ZODB/interfaces.py
A ZODB/branches/shane-poll-invalidations/src/ZODB/tests/testPollableMappingStorage.py
-=-
Modified: ZODB/branches/shane-poll-invalidations/src/ZODB/Connection.py
===================================================================
--- ZODB/branches/shane-poll-invalidations/src/ZODB/Connection.py 2008-12-12 20:27:21 UTC (rev 94004)
+++ ZODB/branches/shane-poll-invalidations/src/ZODB/Connection.py 2008-12-12 21:13:38 UTC (rev 94005)
@@ -94,8 +94,13 @@
# Multi-database support
self.connections = {self._db.database_name: self}
- self._normal_storage = self._storage = db.storage
- self.new_oid = db.storage.new_oid
+ storage = db.storage
+ m = getattr(storage, 'bind_connection', None)
+ if m is not None:
+ # Use a storage instance bound to this connection.
+ storage = m(self)
+ self._normal_storage = self._storage = storage
+ self.new_oid = storage.new_oid
self._savepoint_storage = None
# Do we need to join a txn manager?
@@ -148,6 +153,12 @@
# in the cache on abort and in other connections on finish.
self._modified = []
+ # Allow the storage to decide whether invalidations should
+ # propagate between connections. If the storage provides MVCC
+ # semantics, it is better to not propagate invalidations between
+ # connections.
+ self._propagate_invalidations = getattr(
+ self._storage, 'propagate_invalidations', True)
# _invalidated queues invalidate messages delivered from the DB
# _inv_lock prevents one thread from modifying the set while
@@ -295,6 +306,11 @@
if self._opened:
self.transaction_manager.unregisterSynch(self)
+ # If the storage wants to know, tell it this connection is closing.
+ m = getattr(self._storage, 'connection_closing', None)
+ if m is not None:
+ m()
+
if primary:
for connection in self.connections.values():
if connection is not self:
@@ -323,6 +339,9 @@
def invalidate(self, tid, oids):
"""Notify the Connection that transaction 'tid' invalidated oids."""
+ if not self._propagate_invalidations:
+ # The storage disabled inter-connection invalidation.
+ return
if self.before is not None:
# this is an historical connection. Invalidations are irrelevant.
return
@@ -460,8 +479,23 @@
self._registered_objects = []
self._creating.clear()
+ def _poll_invalidations(self):
+ """Poll and process object invalidations provided by the storage.
+ """
+ m = getattr(self._storage, 'poll_invalidations', None)
+ if m is not None:
+ # Poll the storage for invalidations.
+ invalidated = m()
+ if invalidated is None:
+ # special value: the transaction is so old that
+ # we need to flush the whole cache.
+ self._cache.invalidate(self._cache.cache_data.keys())
+ elif invalidated:
+ self._cache.invalidate(invalidated)
+
# Process pending invalidations.
def _flush_invalidations(self):
+ self._poll_invalidations()
self._inv_lock.acquire()
try:
# Non-ghostifiable objects may need to read when they are
Modified: ZODB/branches/shane-poll-invalidations/src/ZODB/DB.py
===================================================================
--- ZODB/branches/shane-poll-invalidations/src/ZODB/DB.py 2008-12-12 20:27:21 UTC (rev 94004)
+++ ZODB/branches/shane-poll-invalidations/src/ZODB/DB.py 2008-12-12 21:13:38 UTC (rev 94005)
@@ -443,6 +443,10 @@
storage.store(z64, None, file.getvalue(), '', t)
storage.tpc_vote(t)
storage.tpc_finish(t)
+ if hasattr(storage, 'connection_closing'):
+ # Let the storage release whatever resources it used for loading
+ # the root object.
+ storage.connection_closing()
# Multi-database setup.
if databases is None:
Modified: ZODB/branches/shane-poll-invalidations/src/ZODB/MappingStorage.py
===================================================================
--- ZODB/branches/shane-poll-invalidations/src/ZODB/MappingStorage.py 2008-12-12 20:27:21 UTC (rev 94004)
+++ ZODB/branches/shane-poll-invalidations/src/ZODB/MappingStorage.py 2008-12-12 21:13:38 UTC (rev 94005)
@@ -37,7 +37,7 @@
def __init__(self, name='MappingStorage'):
self.__name__ = name
self._data = {} # {oid->{tid->pickle}}
- self._transactions = BTrees.OOBTree.OOBTree() # {tid->transaction}
+ self._transactions = BTrees.OOBTree.OOBTree() # {tid->TransactionRecord}
self._ltid = None
self._last_pack = None
_lock = threading.RLock()
Added: ZODB/branches/shane-poll-invalidations/src/ZODB/PollableMappingStorage.py
===================================================================
--- ZODB/branches/shane-poll-invalidations/src/ZODB/PollableMappingStorage.py (rev 0)
+++ ZODB/branches/shane-poll-invalidations/src/ZODB/PollableMappingStorage.py 2008-12-12 21:13:38 UTC (rev 94005)
@@ -0,0 +1,93 @@
+##############################################################################
+#
+# Copyright (c) Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE
+#
+##############################################################################
+"""An extension of MappingStorage that depends on polling.
+
+Each Connection has its own view of the database. Polling updates each
+connection's view.
+"""
+
+import time
+
+import BTrees
+from ZODB.interfaces import IStoragePollable
+from ZODB.MappingStorage import MappingStorage
+from ZODB.TimeStamp import TimeStamp
+from zope.interface import implements
+
+
+class PollableMappingStorage(MappingStorage):
+ implements(IStoragePollable)
+
+ propagate_invalidations = False
+
+ def __init__(self, name="Pollable Mapping Storage"):
+ MappingStorage.__init__(self, name=name)
+ # _polled_tid contains the transaction ID at the last poll.
+ self._polled_tid = ''
+
+ def bind_connection(self, connection):
+ """Returns a storage instance to be used by the given Connection.
+ """
+ return BoundStorage(self)
+
+ def connection_closing(self):
+ """Notifies the storage that a connection is closing.
+ """
+ pass
+
+ def poll_invalidations(self):
+ """Poll the storage for changes by other connections.
+ """
+ new_tid = self._transactions.maxKey()
+
+ if self._polled_tid:
+ if not self._transactions.has_key(self._polled_tid):
+ # This connection is so old that we can no longer enumerate
+ # all the changes.
+ self._polled_tid = new_tid
+ return None
+
+ changed_oids = set()
+ for tid, txn in self._transactions.items(
+ self._polled_tid, new_tid, excludemin=True, excludemax=False):
+ if txn.status == 'p':
+ # This transaction has been packed, so it is no longer
+ # possible to enumerate all changed oids.
+ self._polled_tid = new_tid
+ return None
+ if tid == self._ltid:
+ # ignore the transaction committed by this connection
+ continue
+
+ changes = txn.data
+ # pull in changes from the transaction log
+ for oid, value in changes.iteritems():
+ tid_data = self._data.get(oid)
+ if tid_data is None:
+ tid_data = BTrees.OOBTree.OOBucket()
+ self._data[oid] = tid_data
+ tid_data[tid] = changes[oid]
+ changed_oids.update(changes.keys())
+
+ self._polled_tid = new_tid
+ return list(changed_oids)
+
+
+class BoundStorage(PollableMappingStorage):
+ """A PollableMappingStorage used for a specific Connection."""
+
+ def __init__(self, common):
+ PollableMappingStorage.__init__(self, name=common.__name__)
+ # bound storages use the same transaction log as the common storage.
+ self._transactions = common._transactions
Modified: ZODB/branches/shane-poll-invalidations/src/ZODB/interfaces.py
===================================================================
--- ZODB/branches/shane-poll-invalidations/src/ZODB/interfaces.py 2008-12-12 20:27:21 UTC (rev 94004)
+++ ZODB/branches/shane-poll-invalidations/src/ZODB/interfaces.py 2008-12-12 21:13:38 UTC (rev 94005)
@@ -953,6 +953,56 @@
# DB pass-through
+class IStoragePollable(Interface):
+ """A storage that can be polled for changes."""
+
+ def bind_connection(connection):
+ """Returns a storage instance to be used by the given Connection.
+
+ This method is optional. By implementing this method, a storage
+ instance can maintain Connection-specific state.
+
+ If this method is not provided, all connections to the same database
+ use the same storage instance (even across threads).
+ """
+
+ propagate_invalidations = Attribute(
+ """A boolean value indicating whether invalidations should propagate.
+
+ ZODB normally sends invalidation notifications between
+ Connection objects within a Python process. If this
+ attribute is false, no such invalidations will be sent.
+ Cross-connection invalidation should normally be enabled, but
+ it adds unnecessary complexity to storages that expect the connection
+ to poll for invalidations instead.
+
+ If this attribute is not present, it is assumed to be true.
+ """)
+
+ def connection_closing():
+ """Notifies the storage that a connection is closing.
+
+ This method is optional. This method is useful when
+ bind_connection() provides Connection-specific storage instances.
+ It lets the storage release resources.
+ """
+
+ def poll_invalidations():
+ """Poll the storage for external changes.
+
+ This method is optional. This method is useful when
+ bind_connection() provides Connection-specific storage instances.
+
+ Returns either a sequence of OIDs that have changed, or None. When a
+ sequence is returned, the corresponding objects should be removed
+ from the ZODB in-memory cache. When None is returned, the storage is
+ indicating that so much time has elapsed since the last poll that it
+ is no longer possible to enumerate all of the changed OIDs, since the
+ previous transaction seen by the connection has already been packed.
+ In that case, the ZODB in-memory cache should be cleared.
+ """
+
+
class IStorageCurrentRecordIteration(IStorage):
def record_iternext(next=None):
Added: ZODB/branches/shane-poll-invalidations/src/ZODB/tests/testPollableMappingStorage.py
===================================================================
--- ZODB/branches/shane-poll-invalidations/src/ZODB/tests/testPollableMappingStorage.py (rev 0)
+++ ZODB/branches/shane-poll-invalidations/src/ZODB/tests/testPollableMappingStorage.py 2008-12-12 21:13:38 UTC (rev 94005)
@@ -0,0 +1,164 @@
+##############################################################################
+#
+# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+
+import unittest
+
+from persistent.mapping import PersistentMapping
+import transaction
+import ZODB.PollableMappingStorage
+from ZODB.DB import DB
+
+
+from ZODB.tests import (
+ BasicStorage,
+ HistoryStorage,
+ IteratorStorage,
+ MTStorage,
+ PackableStorage,
+ RevisionStorage,
+ StorageTestBase,
+ Synchronization,
+ )
+
+class PollableTests:
+
+ def checkCrossConnectionInvalidation(self):
+ # Verify connections see updated state at txn boundaries.
+ # This will fail if Connection doesn't poll for changes.
+ db = DB(self._storage)
+ try:
+ c1 = db.open()
+ r1 = c1.root()
+ r1['myobj'] = 'yes'
+ c2 = db.open()
+ r2 = c2.root()
+ self.assert_('myobj' not in r2)
+
+ storage = c1._storage
+ t = transaction.Transaction()
+ t.description = 'invalidation test'
+ storage.tpc_begin(t)
+ c1.commit(t)
+ storage.tpc_vote(t)
+ storage.tpc_finish(t)
+
+ self.assert_('myobj' not in r2)
+ c2.sync()
+ self.assert_('myobj' in r2)
+ self.assert_(r2['myobj'] == 'yes')
+ finally:
+ db.close()
+
+ def checkCrossConnectionIsolation(self):
+ # Verify MVCC isolates connections.
+ # This will fail if Connection doesn't poll for changes.
+ db = DB(self._storage)
+ try:
+ c1 = db.open()
+ r1 = c1.root()
+ r1['alpha'] = PersistentMapping()
+ r1['gamma'] = PersistentMapping()
+ transaction.commit()
+
+ # Open a second connection but don't load root['alpha'] yet
+ c2 = db.open()
+ r2 = c2.root()
+
+ r1['alpha']['beta'] = 'yes'
+
+ storage = c1._storage
+ t = transaction.Transaction()
+ t.description = 'isolation test 1'
+ storage.tpc_begin(t)
+ c1.commit(t)
+ storage.tpc_vote(t)
+ storage.tpc_finish(t)
+
+ # The second connection will now load root['alpha'], but due to
+ # MVCC, it should continue to see the old state.
+ self.assert_(r2['alpha']._p_changed is None) # A ghost
+ self.assert_(not r2['alpha'])
+ self.assert_(r2['alpha']._p_changed == 0)
+
+ # make root['alpha'] visible to the second connection
+ c2.sync()
+
+ # Now it should be in sync
+ self.assert_(r2['alpha']._p_changed is None) # A ghost
+ self.assert_(r2['alpha'])
+ self.assert_(r2['alpha']._p_changed == 0)
+ self.assert_(r2['alpha']['beta'] == 'yes')
+
+ # Repeat the test with root['gamma']
+ r1['gamma']['delta'] = 'yes'
+
+ storage = c1._storage
+ t = transaction.Transaction()
+ t.description = 'isolation test 2'
+ storage.tpc_begin(t)
+ c1.commit(t)
+ storage.tpc_vote(t)
+ storage.tpc_finish(t)
+
+ # The second connection will now load root[3], but due to MVCC,
+ # it should continue to see the old state.
+ self.assert_(r2['gamma']._p_changed is None) # A ghost
+ self.assert_(not r2['gamma'])
+ self.assert_(r2['gamma']._p_changed == 0)
+
+ # make root[3] visible to the second connection
+ c2.sync()
+
+ # Now it should be in sync
+ self.assert_(r2['gamma']._p_changed is None) # A ghost
+ self.assert_(r2['gamma'])
+ self.assert_(r2['gamma']._p_changed == 0)
+ self.assert_(r2['gamma']['delta'] == 'yes')
+ finally:
+ db.close()
+
+
+class PollableMappingStorageTests(
+ StorageTestBase.StorageTestBase,
+ BasicStorage.BasicStorage,
+
+ HistoryStorage.HistoryStorage,
+ IteratorStorage.ExtendedIteratorStorage,
+ IteratorStorage.IteratorStorage,
+ MTStorage.MTStorage,
+ PackableStorage.PackableStorageWithOptionalGC,
+ RevisionStorage.RevisionStorage,
+ Synchronization.SynchronizedStorage,
+ PollableTests
+ ):
+
+ def setUp(self):
+ self._storage = ZODB.PollableMappingStorage.PollableMappingStorage()
+
+ def tearDown(self):
+ self._storage.close()
+
+ def checkLoadBeforeUndo(self):
+ pass # we don't support undo yet
+ checkUndoZombie = checkLoadBeforeUndo
+
+
+def test_suite():
+ suite = unittest.makeSuite(PollableMappingStorageTests, 'check')
+ return suite
+
+if __name__ == "__main__":
+ loader = unittest.TestLoader()
+ loader.testMethodPrefix = "check"
+ unittest.main(testLoader=loader)
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